A report released by the United States Trade Representative has listed the world's largest BitTorrent indexers, cyberlockers and linking sites as some of the most problematic copyright infringers in the world. In addition to the usual suspects of The Pirate Bay, isoHunt, KickassTorrents and Torrentz, file-hosting service RapidGator and WarezBB make an appearance.

In its latest “Out-of-Cycle Review of Notorious Markets” report the United States Trade Representative (USTR) has listed some of the world’s largest file-sharing sites as venues for prolific copyright infringement.

“The Notorious Markets List identifies selected markets, including ones on the Internet, that are reportedly engaged in substantial piracy and counterfeiting, according to information submitted to the Office of the U.S. Trade Representative (USTR),” the report begins.

Those submissions are supplied by rightsholder groups such as the RIAA and MPAA, who compiled their recommendations a few months ago. The sites included are marked for further investigation because they “exemplify wider concerns” about issues such as copyright infringement.

Unsurprisingly some of the sites listed come from the file-sharing space, and the report begins that section with cautious celebration.

After earlier appearances Megaupload is now absent from the report after being closed in January this year. Gone too is BitTorrent indexing site BTjunkie that closed shortly after, and Demonoid that was shuttered following an investigation in Mexico and Ukraine.

But despite these reported “successes” (Mega will return in January and Demonoid’s tracker is already back online) there is little change at the top of the torrent charts.

BitTorrent Indexers

On the indexing front, public enemy #1 is still The Pirate Bay, a site that remains online “despite the criminal conviction of its founders.”

In second place comes Gary Fung’s isoHunt, the large and impressively long-standing Canada-based site that simply refuses to disappear, despite intense pressure from the MPAA.

In a strong third position is KickassTorrents. The USTR says the site’s popularity has further increased since its inclusion in the December 2011 Notorious Markets report and remains notable “for its commercial look and feel.”

The final indexing position is occupied by meta-search engine Torrentz.eu, a site that carries no torrents of its own but links to results on other services around the web.

BitTorrent Trackers

With Demonoid gone (well, kind of) the USTR feels that Rutracker is now the king of the trackers. This Russia-based site is immensely popular, ranking 15th in Russia according to Alexa and among the top 300 most-visited sites in the world.

Bulgaria-based Zamunda.net and Arenabg.com complete the list after both managed to weather the storm of criminal cases against them.

Despite their appearances in the March 2011 USTR report, both the OpenBitTorrent and PublicBT trackers remain absent from the latest list.

Cyberlockers / Linking

Following the demise of Megaupload, the MPAA and RIAA needed a new cyberlocker bogeyman. They appear to have found one in Rapidgator.

“This cyberlocker has gained popularity and users in the wake of MegaUpload’s closure. It was originally hosted in the United Kingdom (U.K.) but moved to Russia after U.K. enforcement officials shut it down,” the USTR reports.

UK-based Putlocker makes another appearance after being recommended for the Nortorious Markets list by the MPAA in both 2011 and 2012. Ukraine-based Ex.ua, that was briefly shut down earlier this year but quickly reopened, completes the file-hosting entries.

Aside from the Brazil-focused Baixe de Tudo and China’s Gougou, the USTR sees Warez-bb as the major Western threat on the infringing links front, complaining that although links are removed from the site following copyright complaints, they very quickly return.

What will happen to the sites listed above will largely rest on the shoulders of the countries where they are hosted and how susceptible they are to US influence. Whatever happens, 2013 will be an eventful year.